Self-cleaning conduits for hydrocarbon fluids
A self-cleaning conduit for a hydrocarbon fluid. The conduit includes a tube and a movable sleeve. The tube has an interior surface defining a flow passage for the hydrocarbon fluid. The movable sleeve is positioned within the flow passage to abut the interior surface and is movable along the interior surface in response to a change in an operating characteristic of the conduit to break-up deposits on the interior surface.
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The present application claims the benefit of Indian Patent Application No. 202211037977, filed on Jul. 1, 2022, which is hereby incorporated by reference herein in its entirety.
TECHNICAL FIELDThe present disclosure relates to conduits carrying a hydrocarbon fluid, particularly, conduits in gas turbine engines for aircraft.
BACKGROUNDGas turbine engines use hydrocarbon fluids, such as fuels and lubricating oils. Such hydrocarbon fluids are conveyed through the engine in various conduits, and the interior surfaces of these conduits contact the hydrocarbon fluids. Carbonaceous deposits (also known as coke) may form on these surfaces when exposed to the hydrocarbon fluids at elevated temperatures, resulting in carbon becoming attached to these surfaces and building up as deposits on these surfaces.
Features and advantages of the present disclosure will be apparent from the following description of various exemplary embodiments, as illustrated in the accompanying drawings, wherein like reference numbers generally indicate identical, functionally similar, and/or structurally similar elements.
Features, advantages, and embodiments of the present disclosure are set forth or apparent from a consideration of the following detailed description, drawings, and claims. Moreover, the following detailed descriptions are exemplary and intended to provide further explanation without limiting the scope of the disclosure as claimed.
Various embodiments are discussed in detail below. While specific embodiments are discussed, this is done for illustration purposes only. A person skilled in the relevant art will recognize that other components and configurations may be used without departing from the spirit and the scope of the present disclosure.
As used herein, the terms “first,” “second,” and “third” may be used interchangeably to distinguish one component from another and are not intended to signify location or importance of the individual components.
The terms “forward” and “aft” refer to relative positions within a gas turbine engine or vehicle, and refer to the normal operational attitude of the gas turbine engine or vehicle. For example, with regard to a gas turbine engine, forward refers to a position closer to an engine inlet, and aft refers to a position closer to an engine nozzle or an exhaust.
The terms “upstream” and “downstream” refer to the relative direction with respect to fluid flow in a fluid pathway. For example, “upstream” refers to the direction from which the fluid flows, and “downstream” refers to the direction to which the fluid flows.
The terms “coupled,” “fixed,” “attached,” “connected,” and the like, refer to both direct coupling, fixing, attaching, or connecting, as well as indirect coupling, fixing, attaching, or connecting through one or more intermediate components or features, unless otherwise specified herein.
The singular forms “a,” “an,” and “the” include plural references unless the context clearly dictates otherwise.
Here and throughout the specification and the claims, range limitations are combined and interchanged. Such ranges are identified and include all the sub-ranges contained therein unless context or language indicates otherwise. For example, all ranges disclosed herein are inclusive of the endpoints, and the endpoints are independently combinable with each other.
As noted above, coke deposition may occur on surfaces of a gas turbine engine that are exposed to hydrocarbon fluids, such as fuels and lubricating oils, at elevated temperatures. The hydrocarbon fluids flow through various conduits including, for example, tubes, and the inner walls of such conduits are exposed to these hydrocarbon fluids. On such surfaces, coke can build up in considerable thickness, restricting or even blocking the fluid flow in such passages. In other situations, large pieces of coke can shed off these surfaces causing blockages or even damage to downstream components. In some components, these deposits can be removed by periodic maintenance, such as cleaning or replacement of the component. Such maintenance, however, can be expensive and time consuming, and there may be some components where such maintenance is not possible.
Tubes that may be particularly susceptible to such coking are oil tubes located in fairings of engine frames that support the gas turbine engine and, more specifically, a high-pressure shaft and a low-pressure shaft of the gas turbine engine. Oil is used to lubricate various components of the gas turbine engine including, for example, the bearings supporting the high-pressure shaft and the low-pressure shaft. To provide oil to these bearings, the oil flows through the oil tubes located in the engine frames. A portion of these oil tubes is located within the core air flow path of the gas turbine engine, and these portions of the tubes may be subjected to elevated temperature suitable for coke formation, particularly after shutdown during, so-called, soak-back conditions. These oil tubes may be relatively narrow and, as a result of coke formation, may be susceptible to blockages forming in these oil tubes.
The embodiments discussed herein include hydrocarbon fluid conduits, such as an oil tube, that are self-cleaning. Some embodiments employ a mesh sleeve formed of a shape memory alloy (SMA) or bimetallic materials located along the interior surfaces of the hydrocarbon fluid conduit. When the hydrocarbon fluid conduit (oil tube) undergoes the thermal cycling that occurs during normal operation of the gas turbine engine, the mesh sleeve is configured to change in length, breaking up the deposits that have formed on the interior surface of the hydrocarbon fluid conduit. In other embodiments, a sleeve is moved along the interior surface of the hydrocarbon fluid conduit by changes in temperature (like the thermal cycling discussed above) or pressure that occurs in the oil tube during normal operation of the gas turbine engine. Movement of the sleeve breaks ups (or scrapes off) the deposits that have formed on the interior surface of the hydrocarbon fluid conduit. The disrupted coke deposits can then be removed by the natural flow of the hydrocarbon fluid (e.g., oil) past the surface, thus, avoiding the buildup of coke deposits. This is referred to herein as a self-cleaning effect.
The hydrocarbon fluid conduit including the mesh sleeve or movable sleeve discussed herein is particularly suitable for use in engines, such as a gas turbine engine used on an aircraft.
As will be described further below with reference to
Although the aircraft 10 shown in
The turbomachine 104 depicted in
The fan section 102 shown in
The turbofan engine 100 is operable with the fuel system 150 and receives a flow of fuel from the fuel system 150. The fuel system 150 includes a fuel delivery assembly 153 providing the fuel flow from the fuel tank 151 to the turbofan engine 100, and, more specifically, to a plurality of fuel nozzles 162 that inject fuel into a combustion chamber 164 of a combustor 160 of the combustion section 114. The components of the fuel system 150, and, more specifically, the fuel tank 151, is an example of a fuel source that provides fuel to the fuel nozzles 162, as discussed in more detail below. The fuel delivery assembly 153 includes tubes, pipes, conduits, and the like, to fluidly connect the various components of the fuel system 150 to the engine 100. The fuel tank 151 is configured to store the hydrocarbon fuel, and the hydrocarbon fuel is supplied from the fuel tank 151 to the fuel delivery assembly 153. The fuel delivery assembly 153 is configured to carry the hydrocarbon fuel between the fuel tank 151 and the engine 100 and, thus, provides a flow path (fluid pathway) of the hydrocarbon fuel from the fuel tank 151 to the engine 100.
The fuel system 150 includes at least one fuel pump fluidly connected to the fuel delivery assembly 153 to induce the flow of the fuel through the fuel delivery assembly 153 to the engine 100. One such pump is a main fuel pump 155. The main fuel pump 155 is a high-pressure pump that is the primary source of pressure rise in the fuel delivery assembly 153 between the fuel tank 151 and the engine 100. The main fuel pump 155 may be configured to increase a pressure in the fuel delivery assembly 153 to a pressure greater than a pressure within the combustion chamber 164 of the combustor 160.
The fuel system 150 also includes a fuel metering unit 157 in fluid communication with the fuel delivery assembly 153. Any suitable fuel metering unit 157 may be used including, for example, a metering valve. The fuel metering unit 157 is positioned downstream of the main fuel pump 155 and upstream of a fuel manifold 159 configured to distribute fuel to the fuel nozzles 162. The fuel system 150 is configured to provide the fuel to the fuel metering unit 157, and the fuel metering unit 157 is configured to receive fuel from the fuel tank 151. The fuel metering unit 157 is further configured to provide a flow of fuel to the engine 100 in a desired manner. More specifically, the fuel metering unit 157 is configured to meter the fuel and to provide a desired volume of fuel, at, for example, a desired flow rate, to the fuel manifold 159 of the engine 100. The fuel manifold 159 is fluidly connected to the fuel nozzles 162 and distributes (provides) the fuel received to the plurality of fuel nozzles 162, where the fuel is injected into the combustion chamber 164 and combusted. Adjusting the fuel metering unit 157 changes the volume of fuel provided to the combustion chamber 164 and, thus, changes the amount of propulsive thrust produced by the engine 100 to propel the aircraft 10.
The HP shaft 122 and the LP shaft 124 are supported for rotation in one or more bearings 176. One or more turbine frames 180 provide structural load paths from the bearings 176 to the outer casing 106, which forms a backbone structure of the engine 100. The turbine frame shown in
The turbine rear frame 180 comprises an annular, centrally-located hub 182, surrounded by an annular outer ring 184. The hub 182 and the outer ring 184 are interconnected by a plurality of radially-extending struts (not shown). The turbine rear frame 180 may have, for example, six equally-spaced struts around the circumferential direction. The turbine rear frame 180 may be a single integral unit or may be built up from individual components. The struts may be hollow and include a bleed-air port for cooling of the struts. The turbine rear frame 180 may also include a plurality of service tube assemblies 186 mounted in the turbine rear frame 180. The service tube assemblies 186 may be positioned between the struts, and extend between the hub 182 and the outer ring 184. In this example, six service tube assemblies 186 are circumferentially spaced between each of the struts. As will be discussed in more detail below, each service tube assembly 186 includes a hollow service tube that may be used to convey a fluid to and from the inner core of the engine 100. The service tubes may be the hydrocarbon fluid conduits according to embodiments discussed herein and, in the particular embodiment discussed below, the service tube is an oil tube 300 (see
The sumps 210 (depicted as A sump, B sump, or C sump, in
Some of the sumps 210 of the engine 100 are located radially within the core air flow path 121, such as, for example, the bearing 176 (see
The main lubrication system 200 includes at least one oil pump 220 fluidly connected to the oil delivery assembly 204 to induce the flow of oil through the oil delivery assembly 204. The main lubrication system 200 may include, for example, a supply pump 222 configured to draw oil from the oil reservoir 202 and to supply the oil to each sump 210. The supply pump 222 may be positioned downstream of the oil reservoir 202 and upstream of the sumps 210 relative to the flow of the oil within the oil delivery assembly 204. The main lubrication system 200 may also include a plurality of scavenge pumps 224 configured to scavenge (draw) the oil from each of the sumps 210 and to return the scavenged oil back to the oil reservoir 202. One scavenge pump 224 may be used for each sump 210, and each of the scavenge pumps 224 may be positioned downstream of the corresponding sump 210 and upstream of the oil reservoir 202 relative to the flow of the oil within the oil delivery assembly 204. The oil pumps 220 may be driven by the accessory gearbox 212.
The main lubrication system 200 may also include at least one heat exchanger configured to extract heat from the oil. In this embodiment, the main lubrication system 200 includes a fuel-to-oil heat exchanger 232 and an oil-to-oil heat exchanger 234. In this embodiment, the fuel-to-oil heat exchanger 232 and the oil-to-oil heat exchanger 234 are positioned downstream of the supply pump 222 and upstream of the sumps 210 relative to the flow of the oil within the oil delivery assembly 204. A main filter 236 may be positioned between the supply pump 222 and the fuel-to-oil heat exchanger 232 and/or the oil-to-oil heat exchanger 234 to remove any debris from the oil prior to the oil flowing to the fuel-to-oil heat exchanger 232, the oil-to-oil heat exchanger 234, and the sumps 210.
As shown in
Immediately after shutdown, so-called soak back heating occurs. At shutdown, the flow of the oil within the flow passage 302 (see
The oil tube 300 discussed herein is self-cleaning and may employ a movable sleeve to remove the coke forming on the interior surface 322 of the wall 320 (see
Shape memory alloys may undergo a phase change with changing (an increase or decrease) in temperature. Nitinol®, for example, may change between an austenitic phase and a martensitic phase. The temperature (or temperature range) at which this phase change occurs may be referred to as a transformation temperature. The shape memory alloy used to form the mesh 332 of the oil tube 300 preferably has a transformation temperature range appropriate for the thermal cycling of the oil tube 300, discussed above with respect to
The mesh 332 of the mesh sleeve 330 shown in
The mesh 340 shown in
The meshes 350, 360, 370 shown in
The following discussion of the mesh sleeve 330 uses mesh 332 as an example, but the following applies equally to mesh sleeves using the meshes 340, 350, 360, 370, 381, 382, 383, 384, 385, 386, 387, 388, 389, 391, 392, 393, 394, 395, 396, 397, 398, 399.
In the embodiments discussed above, the mesh 332 is formed of a shape memory alloy, but the mesh 332 could also be formed using, for example, bimetal strands 334 having a first metal and the second metal. The two different metals used to form the mesh 332 have different thermal expansion coefficients such that the different thermal expansion coefficients drive movement of the mesh sleeve 330 in the manner discussed above under the thermal cycling of the engine 100. Metals that may be used in the bimetal strands 334 as the first and second metals for the applications discussed herein include, for example, steels, such as stainless steels, titanium, titanium alloys, nickel and nickel alloys such as Inconel®, RENE™, and Hastalloy™.
The oil flowing through the flow passage 302 flows through the flow passage 302 with an oil pressure. The oil thus presses on a circumferential surface 418 of the movable sleeve 412 in the axial direction a of the oil tube 300. The oil presses against the spring force of the spring 414. The size of the circumferential surface 418 and the spring force of the spring 414 are configured such that the oil pressure moves the movable sleeve 412 towards one end of the oil tube 300. The circumferential surface 418 is an example of a contact surface to which a pressure may be applied to move the movable sleeve 412. In this embodiment, the oil pressure and the flow of the oil in the flow passage 302 press the movable sleeve 412 toward the inner end 316 (see
The spring 414 may be any suitable spring, including, for example, a wave spring or a bellows spring. Suitable wave springs include those made by Smalley, of Lake Zurich, Illinois. Preferably, the spring 414 is a spring that is suitable for relatively large distances of travel such that one spring 414 and movable sleeve 412 are used within the oil tube 300 and the movable sleeve 412 covers nearly the entire length of the central section 312 (see
The oil tube 300a is similar to the oil tube 300 discussed above and may be used in place of the oil tube 300 discussed above. The same reference numerals will be used for components of the oil tube 300a of this embodiment that are the same or similar to the components of the oil tube 300 discussed above. The description of these components above also applies to this embodiment, and a detailed description of these components is omitted here. The oil tube 300a of this embodiment is a double-walled tube having an inner wall 324 and an outer wall 326. The interior surface 322 is formed on the inner wall 324, and the inner wall 324 and the outer wall 326 are positioned to define a cavity 304 therebetween. Although shown as circular in this embodiment, the inner wall 324 and the outer wall 326 may have other suitable shapes such as the elliptical shape shown in
The movable sleeve assembly 420 of this embodiment includes the inner movable sleeve 422 and an outer movable sleeve 424. The outer movable sleeve 424 is positioned within the cavity 304 and connected to the spring 414. In this embodiment, the spring 414 is located within the cavity 304. The cavity 304 is fluidly connected to the pressure source, such as the compressor bleed air 22. When the engine 100 is operating, the compressor bleed air 22 is provided to the cavity 304 and presses on a circumferential surface 426 of the outer movable sleeve 424 in the axial direction a of the oil tube 300a. The compressor bleed air 22 presses against the spring force of the spring 414. The size of the circumferential surface 426 and spring force of the spring 414 are configured such that the pressure of the compressor bleed air 22 moves the outer movable sleeve 424 towards one end of the oil tube 300. In this embodiment, the compressor bleed air 22 presses the outer movable sleeve 424 toward the inner end 316 (see
The inner movable sleeve 422 is coupled to the outer movable sleeve 424, and inner movable sleeve 422 moves along with the outer movable sleeve 424. In this embodiment, the inner movable sleeve 422 is magnetically coupled to the outer movable sleeve 424. For example, the outer movable sleeve 424 may be magnetic and the inner movable sleeve 422 may include a plurality of roller balls 428, shown in
The compressor bleed air 22 is used to provide the pressure to move the movable sleeve assembly 430 and, more specifically, the outer movable sleeve 424. To accommodate both the compressor bleed air 22, the first spring 442, and the second spring 444, the oil tube 300b of this embodiment is a triple-walled tube. The oil tube 300b is similar to the oil tube 300a discussed above and may be used in place of the oil tube 300a discussed above. The same reference numerals will be used for components of the oil tube 300b of this embodiment that are the same or similar to the components of the oil tube 300a discussed above. The description of these components above also applies to this embodiment, and a detailed description of these components is omitted here. The oil tube 300b has a middle wall 328 positioned between the inner wall 324 and the outer wall 326. An inner cavity 306 is defined between the inner wall 324 and the middle wall 328, and an outer cavity 308 is defined between the middle wall 328 and the outer wall 326. The outer movable sleeve 424 includes a portion in each of the inner cavity 306 and the outer cavity 308, an inner portion 432 and an outer portion 434, respectively. In this embodiment, the outer cavity 308 is fluidly connected to the pressure source, such as the compressor bleed air 22, and the circumferential surface 426 is located on the portion of the outer movable sleeve 424 in the outer cavity 308 (outer portion 434). The first spring 442 and the second spring 444 are located in the inner cavity 306 and connected to the portion of the outer movable sleeve 424 in the inner cavity 306 (inner portion 432). The middle wall 328 may include a plurality of slots 329, and the inner portion 432 of the outer movable sleeve 424 is connected to the outer portion 434 of the outer movable sleeve 424 by connecting portions 436 through the plurality of slots 329.
Returning to the embodiment discussed above with reference to
During the course of evaluating the variations possible in the design, both the benefits in terms of, e.g., scrapping efficiency vs. reliability or efficiency in removing or mitigating coke, the inventors, discovered, unexpectedly, that there exists a relationship among select features of the mesh 332, the working temperatures of the wall 320 and the oil, and the material of the wall 320 that produced superior results over the other numerous other designs considered. This relationship is referred to by the inventors as the mesh activation parameter (MAP) for lube oil coke cleaning. MAP is a dimensionless factor defined according to the following relationship (1):
The first factor of the MAP, as shown in relationship (1), is referred to herein as the mesh density (V′/V). As noted above, the mesh 332 includes openings 336 and, thus, the volume of the mesh 332 (V′) is less than the volume if the mesh sleeve 330 were solid (V and referred to herein as solid sleeve volume). The mesh density (V′/V) is the volume of the mesh 332 (V′) divided by the solid sleeve volume (V). The volume of the mesh 332 (V′) can be calculated by suitable methods including, for example, calculations from computer-aided design (CAD) models or displacement methods where the mesh is submerged in a liquid and the volume of the displaced liquid is used to calculate the volume of the mesh 332 (V′). The solid sleeve volume (V) can be calculated by using the overall dimensions of the mesh sleeve 330. These volumetric calculations or measurements are taken in the as assembled condition, such as at room temperature.
The second factor of the MAP, as shown in relationship (1), is referred to herein as a working temperature ratio (Toil/Tmetal). The working temperature ratio (Toil/Tmetal) is the ratio of the temperature of the oil (Toil) to the temperature of the wall 320 (Tmetal). These temperatures are taken as the maximum expected normal operating temperatures of the oil and the wall 320, respectively.
The third factor of the MAP, as shown in relationship (1), is referred to herein as a deformation factor (ΔH/H). The mesh sleeve 330 has an initial shape including an axial length and a diameter in the as assembled state. A position on the mesh sleeve 330 also has an initial angular position. This initial axial length, initial diameter, or initial angular position is taken as the initial shape (H). The length, diameter, and/or the angular position of the mesh sleeve 330 will change under the thermal cycling conditions discussed above. The angular position changes by, for example, the mesh sleeve 330 twisting. The change in length, diameter or the angular position is referred to herein as the change in shape ΔH. The deformation factor is the change in shape (ΔH) divided by the initial shape (H), such as the change in length divided by the initial length or the change in diameter divided by the initial diameter or the change in angular position divided by the initial angular position. In some embodiments, the mesh sleeve 330 will grow at higher temperatures and, in other embodiments, the mesh sleeve 330 will shrink at higher temperatures. Accordingly, the absolute value of the deformation factor is used to calculate the MAP.
The fourth factor of the MAP, as shown in relationship (1), is referred to herein as a stiffness ratio (Emesh/Etube). Each of the shape memory alloy used for the mesh 332 and the material used for the wall 320 have an elastic modulus and, more specifically, a Young's modulus. The stiffness ratio (Emesh/Etube) is the ratio of the elastic modulus of the mesh 332 to the elastic modulus of the wall 320 and, more specifically, the ratio of the Young's modulus (Emesh) of the shape memory alloy used for the mesh 332 to the Young's modulus (Etube) of the material used for the wall 320. To the extent there is a temperature dependency of the Young's modulus (elastic modulus), the Young's modulus (elastic modulus) is taken in the as assembled condition, such as at room temperature.
As discussed further below, we have identified a range of the MAP that prevents coke blockages from forming in the oil tube 300 for a set of operational conditions. More specifically, under a given set of scavenge oil temperatures and operational temperatures of the oil tube 300 (conduit), the identified ranges of the MAP will be result in sufficient thermal deformation of the mesh sleeve 330 to break up coke deposits on the interior surface 322 of the wall 320.
Tables 1 and 2 describe exemplary embodiments 1 to 22. Table 1 provides values for the temperature and Young's modulus used to calculate the MAP for different engine environments. Each engine is a high by-pass turbofan engine, such as the engine 100 of
Each of the embodiments uses a mesh sleeve 330 located within the oil tube 300. The mesh sleeve 330 and the mesh 332 may be any one of the mesh sleeves 330 and meshes 332, discussed above. Table 2 gives values used to calculate the MAP for the mesh 332 used in the mesh sleeve 330 of each embodiment. Table 2 also identifies the resultant MAP for each embodiment.
The mesh density (V′/V) may be between one tenth and one. To withstand the operating conditions of the oil tube 300, the mesh 332 of the mesh sleeve 330 will include a minimum number of strands 334, and, thus, the mesh density (V′/V) preferably is greater than one tenth. The mesh density (V′/V) has a limit of a solid sleeve, and, thus, the mesh density (V′/V) preferably is less than one. The density of the mesh impacts the flow dynamics of the oil through the flow passage 302 of the oil tube 300, and different densities, thus, result resulting in different resistances (pressure drops) within the flow passage 302. The mesh density may also impact the amount of movement and, thus, the ability of the mesh sleeve 330 to break up coke deposits with higher densities resulting in less movement. Balancing these considerations and other considerations discussed below, the mesh density (V′/V) is more preferably from two tenths to five tenths.
Some small amount of movement of the mesh sleeve 330 is necessary to break-up the coke deposits, and, in some embodiments, the absolute value of the deformation factor (ΔH/H) may be one tenth or greater. Larger amounts of movement, however, are advantageous in breaking-up the coke deposits and the absolute value of the deformation factor (ΔH/H) is preferably seven tenths or greater. Movements that are too large, however, may introduce other problems such as reduced reliability or blockage. To avoid some of the issues discussed below related to the dynamic response of the mesh sleeve 330 and oil tube 300, the absolute value of the deformation factor (ΔH/H) is preferably nine tenths or less. The absolute value of the deformation factor (ΔH/H), thus, may be from one tenth to nine tenths and, preferably, from seven tenths to nine tenths.
There are a wide verity of shape memory alloys that can be used to move the mesh sleeve 330 in the manner discussed herein and the Young's modulus (Emesh) of these shape memory alloy used for the mesh 332 range from fifty gigapascals to two hundred ten gigapascals. When considered with typical materials used for the oil tube 300 the stiffness ratio (Emesh/Etube), thus, may be from two tenths to ninety-six hundredths. The engine 100 includes many rotating components, as discussed above, producing various vibrations at different excitation frequencies. The mesh sleeve 330 is fixed, as discussed above, so that it can move. Because the mesh sleeve 330 can move, the mesh sleeve may dynamically respond to the vibrations. The selection of the stiffness ratio (Emesh/Etube) in combination with the mesh density (V′/V) and the deformation factor (ΔH/H) is preferably selected to avoid resonate frequencies and other dynamic responses of the mesh sleeve 330 and the oil tube 300, particularly those frequencies that can lead to inelastic acoustic responses and other responses leading to cyclic failure of the oil tube 300. Accordingly, the stiffness ratio (Emesh/Etube) preferably is from five tenths to seven tenths.
One set of more preferred boundaries for the MAP is shown by an area 520. The MAP may be three tenths or less and may be from one tenth to three tenths. As can be seen in
For many of the aircraft applications discussed herein, coke does not form at working temperature ratios (Toil/Tmetal) less than four tenths, and, thus, in some embodiments, the working temperature ratio (Toil/Tmetal) is from four tenths to one.
Further aspects of the present disclosure are provided by the subject matter of the following clauses.
A self-cleaning conduit for a hydrocarbon fluid including a tube and a movable sleeve. The tube has an interior surface defining a flow passage for the hydrocarbon fluid. The movable sleeve is positioned within the flow passage to abut the interior surface and is movable along the interior surface in response to a change in an operating characteristic of the conduit to break-up deposits on the interior surface.
The conduit of the preceding clause, wherein the movable sleeve is a mesh sleeve including a mesh.
The conduit of any preceding clause, wherein the mesh includes a plurality of bimetal strands, and the change in the operating characteristic is a change in temperature of the mesh.
The conduit of any preceding clause, wherein the movable sleeve includes a collar abutting the interior surface of the tube and being movable along the interior surface by the mesh.
The conduit of any preceding clause, wherein the movable sleeve includes a plurality of collars abutting the interior surface of the tube and at least one collar of the plurality of collars being movable along the interior surface by the mesh.
The conduit of any preceding clause, wherein the movable sleeve includes a collar attached to the interior surface of the tube.
The conduit of any preceding clause, wherein the collar is attached to the interior surface of the tube by an interference fit.
The conduit of any preceding clause, wherein the mesh includes a plurality of strands formed of a shape memory alloy, and the change in the operating characteristic is a change in temperature of the mesh.
The conduit of any preceding clause, wherein the shape memory alloy is one of a nickel-titanium alloy, a cobalt-nickel-aluminum alloy, or a nickel-iron-gallium alloy.
The conduit of any preceding clause, further comprising a movable sleeve assembly including the movable sleeve and at least one spring connected to the movable sleeve.
The conduit of any preceding clause, wherein the movable sleeve includes a contact surface, the movable sleeve being positioned in the flow passage to have the hydrocarbon fluid press on the contact surface when the hydrocarbon fluid flows through the flow passage and moves the movable sleeve toward one end of the tube against the spring force of the spring, the flow of the hydrocarbon fluid within the flow passage being the change in the operating characteristic of the conduit.
The conduit of any preceding clause, wherein the movable sleeve is annular and has a circumferential surface, the circumferential surface being the contact surface.
The conduit of any preceding clause, wherein the tube is a multi-walled tube having an inner wall and an outer wall, the interior surface being formed on the inner wall, and the inner wall and the outer wall are positioned to define a cavity therebetween, the cavity being fluidly connected to a pressure source, pressure within the cavity from the pressure source being the change in an operating characteristic of the conduit, and wherein the movable sleeve includes an inner movable sleeve and an outer movable sleeve, the spring being attached to the outer movable sleeve, the outer movable sleeve being positioned within the cavity and including a contact surface, and, when the cavity is receiving pressure from the pressure source, the pressure presses on the contact surface to move the outer movable sleeve toward one end of the tube against the spring force of the spring, the inner movable sleeve being positioned within the flow passage to abut the interior surface, and the inner movable sleeve being coupled to the outer movable sleeve to move along the interior surface to move when the outer movable sleeve moves.
The conduit of any preceding clause, wherein the inner movable sleeve is magnetically coupled to the outer movable sleeve.
The conduit of any preceding clause, wherein the spring is a first spring and the movable sleeve assembly further includes a second spring attached to the outer movable sleeve on an opposite side of the outer movable sleeve from the first spring.
The conduit of any preceding clause, wherein the first spring has a greater spring constant than the second spring.
A lubrication system including an oil reservoir and an oil sump. The oil reservoir is configured to hold oil. The oil sump is fluidly connected to the oil reservoir by the conduit of any preceding clause, wherein the hydrocarbon fluid is the oil.
The lubrication system of the preceding clause, further comprising a pump fluidly connected to each of the oil reservoir and the oil sump and configured to circulate the oil through the conduit.
A gas turbine engine including the lubrication system of any preceding clause, a compressor section, a combustion section, and a turbine section. The compressor section includes at least one rotor, the at least one rotor being configured to compress air flowing therethrough. The combustion section is configured to mix fuel with the compressed air and to combust the mixture of fuel and air to generate combustion products. The turbine section includes at least one turbine configured to be driven by the combustion products, wherein the compressor section, the combustion section, and the turbine section together define at least part of a core air flow path, the conduit being located in the core air flow path.
The gas turbine engine of the preceding clause, further comprising at least one frame, the frame including at least one service tube assembly, the service tube assembly including the conduit.
The gas turbine engine of any preceding clause, wherein the frame includes a plurality of service tube assemblies.
The gas turbine engine of any preceding clause, wherein the frame is a turbine rear frame.
The gas turbine engine of any preceding clause further comprises a shaft connecting the at least one turbine with the at least one rotor, and a bearing supporting the shaft, the frame providing structural load paths from the bearing.
The gas turbine engine of any preceding clause, wherein the lubrication system is configured to provide oil to the bearing.
A self-cleaning conduit for a hydrocarbon fluid including a tube and a mesh. The tube has an interior surface defining a flow passage for the hydrocarbon fluid. The mesh is positioned within the flow passage to abut the interior surface and is movable along the interior surface to break-up deposits on the interior surface. The mesh is characterized by a mesh activation parameter (MAP) from one ten thousandths to six tenths.
The conduit of the preceding clause, wherein the mesh activation parameter (MAP) is from one tenth to three tenths.
The conduit of any preceding clause, wherein the hydrocarbon fluid is oil, and wherein the conduit is configured to be operated at a working temperature ratio from four tenths to one.
The conduit of any preceding clause, wherein the mesh is characterized by an absolute value of a deformation factor from one tenth to nine tenths.
The conduit of any preceding clause, wherein the mesh is characterized by an absolute value of a deformation factor from seven tenths to nine tenths.
The conduit of any preceding clause, wherein the mesh has a mesh density between one tenth and one.
The conduit of any preceding clause, wherein the mesh has a mesh density from two tenths to five tenths.
The conduit of any preceding clause, wherein the mesh is a sleeve.
The conduit of any preceding clause, wherein the mesh is formed of a shape memory alloy.
The conduit of any preceding clause, wherein the shape memory alloy is one of a nickel-titanium alloy, a cobalt-nickel-aluminum alloy, or a nickel-iron-gallium alloy.
The conduit of any preceding clause, wherein the tube is a metal having a Young's modulus, the shape memory alloy has a Young's modulus, and a ratio of the Young's modulus of the mesh to the Young's modulus of the tube is a stiffness ratio. The stiffness ratio is from two tenths to ninety-six hundredths.
The conduit of any preceding clause, wherein the stiffness ratio is from five tenths to seven tenths.
A lubrication system including an oil reservoir and an oil sump. The oil reservoir is configured to hold oil. The oil sump is fluidly connected to the oil reservoir by the conduit of any preceding clause, wherein the hydrocarbon fluid is the oil.
The lubrication system of the preceding clause further comprises a pump fluidly connected to each of the oil reservoir and the oil sump and configured to circulate the oil through the conduit.
A gas turbine engine including the lubrication system of any preceding clause, a compressor section, a combustion section, and a turbine section. The compressor section includes at least one rotor, the at least one rotor being configured to compress air flowing therethrough. The combustion section is configured to mix fuel with the compressed air and to combust the mixture of fuel and air to generate combustion products. The turbine section includes at least one turbine configured to be driven by the combustion products. The compressor section, the combustion section, and the turbine section together define at least part of a core air flow path, the conduit being located in the core air flow path.
The gas turbine engine of the preceding clause, further comprising at least one frame, the frame including at least one service tube assembly, the service tube assembly having the conduit.
The gas turbine engine of any preceding clause, wherein the frame includes a plurality of service tube assemblies.
The gas turbine engine of any preceding clause, wherein the frame is a turbine rear frame.
The gas turbine engine of any preceding clause further comprises a shaft connecting the at least one turbine with the at least one rotor and a bearing supporting the shaft, the frame providing structural load paths from the bearing.
The gas turbine engine of any preceding clause, wherein the lubrication system is configured to provide oil to the bearing.
A method of installing a movable sleeve into a conduit for a hydrocarbon fluid. The movable sleeve is a mesh sleeve including a mesh, and the conduit includes a tube. The method includes crimping the mesh sleeve and inserting the crimped mesh sleeve into the tube.
The method of the preceding clause, wherein the mesh includes a plurality of strands formed of a shape memory alloy.
The method of the any preceding clause, wherein the mesh sleeve is crimped at a temperature and the mesh sleeve is inserted into the tube at a temperature maintaining the mesh of the mesh sleeve in the same metallurgical phase as the metallurgical phase used in the crimping step.
The method of the any preceding clause, further comprising heating the mesh sleeve to expand the crimped mesh sleeve within the tube.
The method of the any preceding clause, further comprising maintaining a crimping force as the crimped mesh sleeve is inserted into the tube and releasing the crimping force to expand the crimped mesh sleeve within the tube.
Although the foregoing description is directed to the preferred embodiments, other variations and modifications will be apparent to those skilled in the art, and may be made without departing from the spirit or the scope of the disclosure. Moreover, features described in connection with one embodiment may be used in conjunction with other embodiments, even if not explicitly stated above.
Claims
1. A self-cleaning conduit for a hydrocarbon fluid, the conduit comprising:
- a tube having an interior surface defining a flow passage for the hydrocarbon fluid; and
- a movable sleeve including an attachment portion and a movable portion, the attachment portion being attached to the tube to position the movable sleeve within the flow passage to abut the interior surface, the movable portion of the movable sleeve being movable along the interior surface in response to a change in an operating characteristic of the conduit to break-up deposits on the interior surface.
2. The conduit of claim 1, wherein the movable sleeve is a mesh sleeve including a mesh.
3. The conduit of claim 2, wherein the mesh includes a plurality of bimetal strands, and the change in the operating characteristic is a change in temperature of the mesh.
4. The conduit of claim 2, wherein the movable sleeve includes a collar abutting the interior surface of the tube and being movable along the interior surface by the mesh.
5. The conduit of claim 2, wherein the mesh includes a plurality of strands formed of a shape memory alloy, and the change in the operating characteristic is a change in temperature of the mesh.
6. The conduit of claim 1, further comprising a movable sleeve assembly including the movable sleeve and at least one spring connected to the movable sleeve.
7. The conduit of claim 6, wherein the movable sleeve includes a contact surface, the movable sleeve being positioned in the flow passage to have the hydrocarbon fluid press on the contact surface when the hydrocarbon fluid flows through the flow passage and moves the movable sleeve toward one end of the tube against the spring force of the spring, the flow of the hydrocarbon fluid within the flow passage being the change in the operating characteristic of the conduit.
8. The conduit of claim 7, wherein the movable sleeve is annular and has a circumferential surface, the circumferential surface being the contact surface.
9. A lubrication system comprising:
- an oil reservoir configured to hold oil; and
- an oil sump fluidly connected to the oil reservoir by the conduit of claim 1, wherein the hydrocarbon fluid is the oil.
10. The lubrication system of claim 9, further comprising a pump fluidly connected to each of the oil reservoir and the oil sump and configured to circulate the oil through the conduit.
11. A self-cleaning conduit for a hydrocarbon fluid, the conduit comprising:
- a tube having an interior surface defining a flow passage for the hydrocarbon fluid, wherein the tube is a multi-walled tube having an inner wall and an outer wall, the interior surface being formed on the inner wall, and the inner wall and the outer wall are positioned to define a cavity therebetween, the cavity being fluidly connected to a pressure source, and
- a movable sleeve assembly including an inner movable sleeve, an outer movable sleeve, and a spring attached to the outer movable sleeve, the outer movable sleeve being positioned within the cavity and including a contact surface, when the cavity is receiving pressure from the pressure source, the pressure presses on the contact surface to move the outer movable sleeve toward one end of the tube against the spring force of the spring, and when the cavity is receiving pressure from the pressure source, the spring force of the spring moves the outer movable sleeve toward one end of the tube,
- wherein the inner movable sleeve is positioned within the flow passage to abut the interior surface, and the inner movable sleeve being coupled to the outer movable sleeve to move along the interior surface to move when the outer movable sleeve moves.
12. The conduit of claim 11, wherein the inner movable sleeve is magnetically coupled to the outer movable sleeve.
13. The conduit of claim 11, wherein the spring is a first spring and the movable sleeve assembly further includes a second spring attached to the outer movable sleeve on an opposite side of the outer movable sleeve from the first spring.
14. The conduit of claim 13, wherein the first spring has a greater spring constant than the second spring.
15. A gas turbine engine comprising:
- a lubrication system including an oil reservoir configured to hold oil and an oil sump fluidly connected to the oil reservoir by a conduit, the conduit including: a tube having an interior surface defining a flow passage for the oil; and a movable sleeve positioned within the flow passage to abut the interior surface and being movable along the interior surface in response to a change in an operating characteristic of the conduit to break-up deposits on the interior surface;
- a compressor section including at least one rotor, the at least one rotor being configured to compress air flowing therethrough;
- a combustion section configured to mix fuel with the compressed air and to combust the mixture of fuel and air to generate combustion products; and
- a turbine section including at least one turbine configured to be driven by the combustion products,
- wherein the compressor section, the combustion section, and the turbine section together define at least part of a core air flow path, the conduit being located in the core air flow path.
16. The gas turbine engine of claim 15, further comprising at least one frame, the frame including at least one service tube assembly, the service tube assembly including the conduit.
17. The gas turbine engine of claim 16, wherein the frame includes a plurality of service tube assemblies.
18. The gas turbine engine of claim 16, wherein the frame is a turbine rear frame.
19. The gas turbine engine of claim 16, further comprising a shaft connecting the at least one turbine with the at least one rotor; and
- a bearing supporting the shaft, the frame providing structural load paths from the bearing.
20. The gas turbine engine of claim 19, wherein the lubrication system is configured to provide oil to the bearing.
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Type: Grant
Filed: Nov 11, 2022
Date of Patent: Sep 17, 2024
Patent Publication Number: 20240001324
Assignee: GENERAL ELECTRIC COMPANY (Evendale, OH)
Inventors: Ravindra Shankar Ganiger (Bengaluru), Hiranya Nath (Bengaluru), Thomas D. Woodrow (Wyoming, OH), Scott Alan Schimmels (Miamisburg, OH), Arvind Namadevan (Bengaluru), Mohan Raju (Bengaluru), Subramani Adhiachari (Bengaluru), Prasant Bilaiya (Bengaluru), Rajesh Kumar (Bengaluru)
Primary Examiner: Michael R Mansen
Assistant Examiner: Mark K Buse
Application Number: 18/054,739
International Classification: F16N 39/00 (20060101); B01J 19/00 (20060101);